6
–
2
6.1
Socket Event Register
This register indicates a change in socket status has occurred. These bits do not indicate what the change is, only
that one has occurred. Software must read the socket present state register for current status. Each bit in this register
can be cleared by writing a 1 to that bit. The bits in this register can be set to a 1 by software through writing a 1 to
the corresponding bit in the socket force event register. All bits in this register are cleared by PCI reset. They can be
immediately set again, if, when coming out of PC Card reset, the bridge finds the status unchanged (i.e., CSTSCHG
reasserted or card detect is still true). Software needs to clear this register before enabling interrupts. If it is not cleared
and interrupts are enabled, then an unmasked interrupt is generated based on any bit that is set. See Table 6
–
2 for
a complete description of the register contents.
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Name
Socket event
Type
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
Default
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Name
Socket event
Type
R
R
R
R
R
R
R
R
R
R
R
R
RWC
RWC
RWC
RWC
Default
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Register:
Offset:
Type:
Default:
Socket event
CardBus Socket Address + 00h
Read-only, Read/Write to Clear
0000 0000h
Table 6
–
2. Socket Event Register Description
BIT
SIGNAL
TYPE
FUNCTION
31
–
4
RSVD
R
These bits return 0s when read.
3
PWREVENT
RWC
Power cycle. This bit is set when the PCI1620 detects that the PWRCYCLE bit in the socket present state
register (offset 08h, see Section 6.3) has changed. This bit is cleared by writing a 1.
2
CD2EVENT
RWC
CCD2. This bit is set when the PCI1620 detects that the CDETECT2 field in the socket present state
register (offset 08h, see Section 6.3) has changed. This bit is cleared by writing a 1.
1
CD1EVENT
RWC
CCD1. This bit is set when the PCI1620 detects that the CDETECT1 field in the socket present state
register (offset 08h, see Section 6.3) has changed. This bit is cleared by writing a 1.
0
CSTSEVENT
RWC
CSTSCHG. This bit is set when the CARDSTS field in the socket present state register (offset 08h, see
Section 6.3) has changed state. For CardBus cards, this bit is set on the rising edge of the CSTSCHG
signal. For 16-bit PC Cards, this bit is set on both transitions of the CSTSCHG signal. This bit is reset by
writing a 1.
This bit is cleared only by the assertion of GRST when PME is enabled. If PME is not enabled, then this bit is cleared by the assertion of PRST
or GRST.